Luke entered the ring on Tuesday by sharing a photo that shows the Chris and a group of friends enjoying a few beers in the sun. The group pic is hijacked, however, by the actor's bulging muscles glistening in the sunlight.

"Hey @chrishemsworth do you even lift bro? @lukemun @emerysurfboards" Luke chided his brother in the caption. Obviously that was a rhetorical question.

The bro battle actually began back in October when Liam posted an Instagram photo of his dog Tani chewing on a Thor action figure. "Tani's favorite chew toy #Thorsday" he captioned the photo of the mangled doll in the dog's mouth: